Multichannel audio systems or sound distribution systems are now commonly referred as home entertainment systems. These systems utilize multichannel audio signals to provide a sound field distribution characteristic of “real life” or concert hall events.
Dolby™ surround sound systems, one brand of multichannel home entertainment systems, utilize separate amplifiers for each sound channel and therefore require a separate audio cable to connect the amplifier to each speaker or sound reproducing device (speaker). The latest Dolby system, designated “7.1,” (seven surround speakers and one subwoofer speaker) includes seven amplifiers, each with an output and correspondingly seven surround speakers situated at different locations within the home entertainment area. Earlier surround sound systems used five or fewer speakers. All such sound systems require two separate electrical conductors to connect the designated amplifier to each speaker.
In a wireless sound distribution system a multichannel amplifier amplifies a composite digital audio signal from an audio source and distributes the audio signal intended for a specific channel (a speaker may be referred to as a channel) to a wireless transmitter dedicated to that audio channel. A wireless receiver located within or proximate an enclosure of the intended speaker receives the digital audio signal from the associated transmitter. The received signal is then supplied to an audio amplifier for the intended speaker. After amplification the signal is capable of driving the speaker or another sound reproducing device. The channel audio signals are time phased for accurate and realistic sound reproduction at the speaker locations, thereby providing a “real life” sound experience.
Prior art wireless speaker systems suffer from poor audio fidelity, signal drop-out and poor synchronization between audio channels (i.e. objectionable time delays between channels). These effects are due in some cases to the use of the common Bluetooth wireless communications protocol to transmit the signals to each speaker of the home entertainment system. A different communications protocol may be required to avoid these problems. Known solutions may not be feasible for high fidelity surround-sound home theater audio systems due to bandwidth limitations of the selected protocol and hence poor sound fidelity. These system may not be capable of simultaneously handling all sound channels without objectionable time delays between channels.
In accordance with common practice, the various described device features are not drawn to scale, but are drawn to emphasize specific features relevant to the invention. Like reference characters denote like elements throughout the figures and text.